Metal clad switch-gear



March 15, 1960 Filed April 1, 1958 H. A. HIDDE NIJLAND METAL CLADSWITCH-GEAR '2 Sheets-Sheet 1 March 15, 1960 H. A. HlDDE NIJLAND2,928,922

METAL CLAD SWITCH-GEAR Filed April 1, 1958 2 Sheets-Sheet 2 f 25 I W E31\ m FIG.3

United States Patent METAL CLAD SWITCH-GEAR Hendrik A. Hidde Nijland,Laren, Netherlands, assignor to N.V. COQ, Utrecht, Netherlands, a Dutchcompany Application April 1, 1958, Serial No. 725,708

Claims priority, application Netherlands April 1, 1957 Z'Claims. (Cl;200-163) I Therinvention relates to metalclad switclkgear for highvoltages, comprising a plurality of. switching units, at least oneswitch contained in eachunit, bus-bars inter.- connecting said switchingunits, a stationary earthed metal envelope containing insulatingmaterial and surrounding all conductors of the switch gear, which, inoperation are under. tension, leading-in conductors insulatedly passedthrough the wall of said envelope, stationary terminal contactsconnected to said leading-in conductors, stationary terminal contactsconnected to the. bus-bars, sets of 'cooperating fixed and movableswitching contacts, connecting contacts directly electrically connectedto the fixed switching contacts, each set of cooperating switchingcontacts and the connecting contacts connected thereto-constituting acomplete switching element, said connecting contacts cooperating withsaid terminal contacts and thereby permitting the switching elements tobe inserted into and-removed from the envelope when the terminalcontacts are under tension.

Switch-gear and switches for such switch-gear of the kind referred toare already known in many arrangements. Reference is made to the Dutchpatent specifications Nos. 47,529 and 67,638 and published Dutch patentapplication No. 88,800. In the switches and the switchgear disclosed bythese patent papers the switching contacts are accommodated in switchingchambers surrounded by insulating walls and provided within earthedmetal casings filled with an insulating fluid. The fixed switchingcontacts of said switches are detachably connected with leading-inconductors passed through the walls of said casings and are used for theconnection to busbars, other parts of the switch-gear or cables of thepower network. The bus-bars of'said switch-gear are accommodated withinindividual metal clad chambers. The invention has for its object toprovide metal clad switch-gear of which the construction is considerablysimplified and requires less space than switch-gear of knownconstruction. It consists in that the metal envelope of all switchingunits is formed as a common stationary casing and both the switches andthe bus-bars are accommodated in said casing.

The construction according to the invention has the advantage that itrequires less expensive leading-in insulators, the additional advantageof which is that, when insulating liquid is used, the risk of leakage issmaller. Moreover, the switch-gear may be made more compact and bothmaterial and labor are saved. Finally the assembling of the switch-gearis simplified, since the construction thereof is such, that big artsthereof can be completed and assembled before they are placed into themetal casing.

According to the invention fixed tubes of insulating material may bemounted within the casing, said tubes surrounding the switching elementsand supporting on their inner surface the terminal contacts and on theirouter surface the bus-bars. Said insulating tubes have a doublefunction, viz. they act as insulating screens and ice as supportinginsulators for the bus-bars and the terminal contacts. Said tubes mayextend throughout the entire height of the metal casing and their innerspace may be separated thereby from the surrounding insulating fluid.The tubes may also terminate within the metal case, so that theybecome'filled with the surrounding insulating fluid.

For the connection of the "power network or other parts of theswitch-gear connecting conductors passed through the metal casing arerequired. Theseconnecting conductors must be positioned inlead-ininsulators of definite length. Consequently, the shape and thedimensions of the metal casing depend also onsaid leadin conductors.

The loss of space due to the provision'of the leadingin conductors maybe reduced, when said conductors and the bus-bars are mounted on thesame side of the switching elements. In that case the metal envelope ofthe switching units may advantageously be shaped as one single oblongrectangular through having plane vertical walls, through one of the longwalls of which the leading-in conductors are passed. Said trough may beprovided with cover plates for closing it on the top and the switchingelementsmay be suspended from and the driving mechanism for the movableswitching contacts may be mounted on said cover plates.

For the elucidation of the invention reference ismade to theaccompanying drawing. Therein is:

Fig. l a vertical sectional view of'switch-gear. according to theinvention.

Fig. 2 a cross-sectional view taken on line II-II in Fig. l and Fig. 3partly'a sectional view and partly an elevational view of switch-gearas-shown in Figs. 1 and 2 completed with a compartment provided'withfuses. i

In Figs. 1 and 2 an oblong rectangular earthed metal casing or trough isdesignated by 1. Mounted in said casing are two or more juxtaposedthree-phase switches, of which each phase comprises a switching elementsuspended from a cover plate 2, on which the driving mechanisms 3 forthe movable switching contacts of said switches are positioned. Eachswitching element consists of a movable switching rod 4, a fixedswitching contact 5 permanently contacting said rod and a fixedswitching contact 6 cooperating with the switching rod 4. The switchingcontacts 5 and 6 are held at a distance from one another by means of atube 7 of insulating material and they are suspended from the coverplate2 by means of an insulating tube 8. The fixed switching contact 5 formsa unit with a metal contact ring 9 to which outward projecting resilientconnecting contacts 10 are secured. Said connecting contacts cooperatewith a ringshaped terminal contact 11, connected to a connectingconductor 12, which is insulatedly passed through a vertical wall of thecasing 1 by means of leading-in insulators 13. Directly attached to thefixed switching contact 6 1s a bushing contact 14, which engages arod-shaped counter-contact 15.

The terminal contact 11 and the countercontact 15 are supported by atube 16 of insulating material, which is placed'on the bottom of thecasing 1 and surrounds the switching element. The counter-contact 15 issupported by a terminal member 17 passed through a hole in the wall ofthe tube 16 and the portion of said terminal member projecting outwardsfrom said tube supports a bar 18 of the three-phase bus-bar system 18,19, 20.

Consequently, the bus-bars 18, 19, 26 are accommodated in the casing 1,in which also the switches are placed. Cables of the outer power network may be connected to the leading-in conductors 12. These conductorsmay also lead to other compartments of the switch-gear. The tube 16 mayextend to an intermediate plate 21, so that the space within said tubeis separated from the space surrounding said tube and for instancecontaining insulating liquid. However, in many cases it is not necessaryto use such long tubes 16.

In the embodiment illustrated in Fig. 3 the switches accommodatedtogether with the bus-bars in one and the same casing 1 in the mannershown in Fig. l are connected to fuses 23 positioned within a secondmetal casing 22. Said fuses are detachably mounted within an insulatingtube 24 extending throughout the entire height of the casing 22. Theelectric connection is carried out by means of cooperating contact rings25, 26 and 27, 28. The contact ring 27 is connected by means of aconductor 29 to the conductor of a leading-in insulator 3t) terminatingoutside the casing 22 into a terminal box 31 for a cable 32. The casing22 may be filled with insulating liquid and the fuses may be surroundedby air contained in the tube 24. By means of a handle 33 the fuses 23may be removed from or inserted into the casing 22.

What I claim is: I

1. In a high voltage metal clad switch-gear comprising, an electricallygrounded metal casing, a cover plate on said casing, polyphase bus barsin said casing, a plurality of circuit-breakers in said casing, eachcircuitbreaker comprising for each phase, first elongated, tubular meanssuspended from said cover plate and made of insulating material, a firstfixed contact mounted on said first tubular means extending radiallyinwardly thereof, a second fixed contact electrically connected to acorresponding bus bar and mounted on said first tubular means disposedaxially spaced from the first fixed contact, second elongated, tubularmeans disposed coaxial with the first tubular means extendingcircumferentially along a part of the axial length thereof, a thirdfixed contact mounted on said second tubular means extending radiallyinwardly thereof, means providing electrical contact between the thirdfixed contact and said first contact, a lead-in conductor electricallyconnected to the third fixed contact, a make-and-break, movable,electrically conductive rod contact operable axially of the firsttubular member to a first operative position bridging the first and second fixed contacts and to a second position disengaged from the secondfixed contact, operator mechanism mounted on said housing for operatingthe movable contact.

2. In a high voltage metal clad switch-gear comprising, an electricallygrounded metal casing defining a compartment, acover plate on saidcasing, polyphase bus bars in said compartment, a plurality ofcircuit-breakers in said compartment, each circuit-breaker comprisingfor each phase, first elongated, tubular means suspended from said cover'plate and made of insulating material, a first fixed contact mounted onsaid first tubular means extending radially inwardly thereof, a secondfixed contact electrically connected to a corresponding bus bar andmounted on said first tubular means disposed axially spaced from thefirst fixed contact, second elongated, tubular meansdisposed coaxialwith the first tubular means extending circumferentially along a part ofthe axial length thereof, a third fixed contact mounted on said secondtubular means extending radially inwardly thereof, means mounting thebus bars on said second tubular means, means providing electricalcontact between the third fixed contact and said first contact, alead-in conductor electrically connected to the third fixed contact, amake-andbreak, movable, electrically conductive rod contact operableaxially of the first tubular member to a first operative positionbridging the first and second fixed contacts and to a second positiondisengaged from the second fixed contact, operator mechanism mounted ontop of said housing for operating the movable contact.

References Cited in the tile of this patent UNITED STATES PATENTS2,287,250 7 Ileman June 23, 1942

